trepa1sd

I put 15W-50 Mobil 1 Extended Performance oil in my 89 5.0. It has 116K on it and I just bought it. Anyway, I figure the heavier weight is OK because of the mileage and the fact I live in a hot climate (El Paso, TX). I replaced the rear main right after I bought the car so the pavement is clean under my car. I have burned about 2 quarts of oil though, in about 1000 miles. Am I burning through oil as a result of synthetic or what? Also, is 15W-50 to heavy?

97targa

Since you checked out you lower half, and if it seems to be solid enough to depend on. The problem is in your valvetrain. Don't mess around trying to fix a boo-boo. Throw those heads right in the garbage/or swap if needed for core, and buy yourself some GT-40 heads. Around $700 w/gaskets and new hardware. This will stop that oil consumption and put about 25-30 hp in the bank. Easy, Easy fix. And no I don't think 15-50 is too heavy for a motor with the cam in the block.

redstallion

How do you know his oil consumption isn't due to worn rings???

He didn't give us any results to a compression test.

PRO50SC

That's what I run in mine

99saleen351r

Is it blowing a puff of white smoke during shifts??Sounds to me like it could be bad valve seals

alexr

im not sure about the 5.0s and whether they burn oil or not, but i run 20w-50 to minimize that, and it runs perfectly fine.